As humans, we use auditory information in many ways. Perhaps most importantly, the production and comprehension of speech is one of the fundamental ways in which we communicate and interact with one another. Songbirds also use vocalizations to interact with one another, and song learning is an attractive and widely used model for studying the basic neuronal mechanisms involved in the production and comprehension of complex vocalizations such as speech. To fully understanding how the song system (a group of interconnected nuclei that are specialized for song perception and production) works, one must understand the auditory input to the song system. However, relatively little is known about auditory processing, particularly processing of complex sounds such as song, in the nuclei that link the auditory system with the song system. I propose to examine the neural processing of complex synthetic and real song in two such nuclei: Field L and cHV. The first aim is to characterize the response properties of neurons in these two areas using conventional methods and by estimating their spectral temporal receptive fields (STRFs). Results from the two methods will be compared. The second aim is to determine if neurons in these two areas are tuned to the species-specific song and, if so, to what specific features. The third aim is to build a framework for understanding how data obtained from these two areas in anesthetized birds can be linked with that obtained in awake birds.